Liquid pump



W. EICKELE July 22, 1952 LIQUID PUMP Filed' April 19. 1950 n 0 0 .l 1 w EN im. iw. JFU w -M n, 0 -u H Y `10.

www C eze WMZ-67" E Patented July 22, 1952 UNITED STAT Bianca; L

l This invention .relates to improvements' ,nin -liquid pumps.l I nparticular, the invention Aisdirectedlto pumps. of a planetary piston type :or style, vin whichv 'a cylindrical impeller iis caused to ..gyrate .within a larger cylindrical pumping- Vcompartment.to driveV fluid therethrough by cyclic vtransposition of the clearance space between the impeller'and thel pumping compartment walls.

Planetary pumps as -av-class. Ye'iiective units, relatively inexpensive to construct and particularly useful for :moderate pressures in pumping luidsiwhich contain solids as 'could deleteriously interfere with. mechanical .com-

ponents/of gear or other types of pumps. vThe direction oi friction'al engagement between .the impeller and the pumping compartment lsur-- face does not reverse, as in the case of a'reciproleating pump,and hence solids are readily-carried from intake to discharge. In order to ,m'ain- 1 tain'adequate sealing engagement of the impeller and the compartment walls under varyingcondit-ions of pressure and temperature, and also to .resist destruction by entrained solids, the impellers are preferably constructed either in'whole f or in part Jof a yielding deformable material such vas rubber or synthetic rubber. f f

.Advanced technique in materialsand in processes of molding synthetic rubber and other deformable plastics lhas made .it possible'to yenlarge the field of application for planetary impellerpumps particularly with regardto uses for high pressures. Thus, instead of using 'simple planetary pumps for moderate pressurelwork in the range up to 30 pounds yper square inch, these pumps may now be yspecified' for relatively higher pressures. Attendant with using the higher pressures is the requirement for impellers which will withstand the resulting increase in stresses v and maintain pump efciency s wear resistantmaterial; the insert and the mold- `ed-mai',e1'ifil covering being 'proportioned so as zto :present .an efficient and effective combination ifor optimum: manufacturing conditions and utility. 4

With the above objects in mind, asvwell as -otherslaivhich will become apparent during-a corissideration of th'e following detailedspecication, ftheinvention comprises vrthe construction Iand are simple and combination of.Y parts as are hereinafter 'fully described, Ait beingunderstoodthat ther disclosure is merely illustrative of the principle'slof` .my invention and that obvious changes may be fmade :in the-"details of,constructi'o'n and the arrange- A-ment fof parts-whicharewith the scope :of-the .appendedfclaims y S Inthe drawing: 'iwf Figureiliis fa cross-sectional elevation vieWl-of Aa planetarypiston `'pump which 'incorporates Vieaturesoimy invention, f Y

Figure' 2 'is a vertical cross section view taken through the 'pump of 'Figure '1 on line-2 2, f.

Figure 3 `:is a top plan view 'of' an insert'iused vin the construction yof the impellerrfor thepum'p of Figuresl :and 2,'withlaidiagrammatic'rout- :line :of ythe fmoldedf coveringl therefor;v and Figure-4 is a verticalrcrosssection View ofthe rinsert of Figure 3 taken on line 4 4.- 'f. vReferring to the drawingl'igure 1,L'creates a hollow housing I0 bymatingandisecuringftogetheraipair of metallicvhalfhousingsectons I0 and 10" each halfssection beingvv provided with a suitable anti-friction' .bushing II within'which :is journalled a rotatable vpumpshaft. I2. A:A'ring vgasket I 81in grooves orr channels outlining the mating half sections provides` 'a liquid seal vtherebetween. The open space.V formed within vthe pump housing structure I0, see alsofFigure 2, includes a vsubstantially cylindrical pumping compartment above.v which is an irregularly shaped open space .forintake and discharge of liquid being. pumped. The right hand. endfsof shaft I2 terminates within a closedboss and ythe left hand'end ofthe shaftprojects `out ofthe housing vfrom an openV boss to permit 4connection with a suitable source of power as' an electric` motor. .A liquid 'seal is Vprovided on the -end of thesha'ft projecting from `the ,housing iincluding' a .deformable ring V`gasket I3v having fan annular groove on the inner' face 'thereonthe latter of which accommodates fa"coil compression spring I4 interposed between the gasket Iand bushing I I to press against the gasket andvbushing llltopress against the :gasket .and deform it radially into liquid :sealing engagement Ywith theshaft and with the inner cylindrical surface of the open boss. 4vThrust washer I5 clearing shaft .I2 forms an abutment for gasket I3 andA is secured inplace by thezuse of Vknurled cap nut I6 which threadedly engages the outsidesurface of the boss. and a lock nut'I'Ilretains cap nut `II in an adjusted position.

Shaft I2; Within'housing 20,'is provided'w'ith two pairs of opposed flats I9 which engagel two C-lshaped 'metallic'eccentrics 20 assembled thereover, the eccentrics inturn being engaged'by the two cylindrical impeller's' 2I closely iitted thereover. Impellers 2I are'nested securelyk against the inner :end 'faces of thepumping V'co'inpartpumping compartment at the joint of the mat-Lv ing housing sections and also includes a Da il'of ...3:`

flat fibre disc gaskets 24 for rotative sealingl against shaft |2. Fibre gaskets 24,'furthermore', y

vcore, a certain shrinkage takes place which conprovide wearing surfaces against` which eccen.. .r

trics 20 and impellers 2| may slide, and in 'this manner the pump is effectively sealedS intofftwo separate pumping compartments. At the same time, shaft I2 is confined bythe assemblyde- -scribed'against movement axially of .the pumping compartment. Y ;r Impellers 2| are substantially cylindrical in exi ternal form, excepting atthe top portions, where they are rectangularly grooved asiat 25 topro-` vide engagement with the metal. divider plate 30 which is removably aixed to, the inner surface ofthe pumping compartment,- depending downwardly therefrom. During pumping, plate 30 serves to restrain the impellers against rotation .while permitting gyration, and a sliding liquid' seal is maintained in the slots 25 at the-surfaces of lcontact with divider; 3|).V lSince dividerll eX- .tends continuously between the-ends of4 the pumping compartment,f.intake on .'the. left side,`

Figure is partitionedsfrom discharge on the right side. Divider plate-.3D also engages a closely fitted slot Aon the disc-like compartment divider 22 to avoid any tendency. -for .that part torotate duringpumping.; y j

To impart maximum rigidity to impeller 2| .and yet. retain the advantages of the .deformable impeller materials. as 'hereinbefore considered,

I construct the impeller with a substantially .cy-4 lindrical hollow. metallic core 26, Figures 3 and 4,. completely-shrouded With-.molded synthetic rubber 21 or the like. Light weight metalsuch as aluminum is preferablyused for lthe core, the upper portion of whichis grooved as' at v25' to. provide for the .slot 25 in the externalim- :peller configuration. Flanking groove 25 inbthe 'core 26 are ridges ..0r. protuberances 28 which .project diametricallyto the extent :that they lie slightly. under;y the outside-.diameters of the 'iinished impeller, thus reinforcing the molded covering adjacent theslot. .,Ridges 28 are intersected transversely with `a series of parallel. concentricou'tside groovesY 28,f:.the.latter of. which ;run .continuously fof the external @periphery of ecol-Q26 and provide for vkeying the .molded covering therewith while permitting'a limitedde'- gree of. yielding-of 'covering.2'|. With Arespect to thecore. .L-f y The internal' bore vof core 2G is'provided with grooves in the formiof a squarer threa'duZB.' interlockingwith the molded rubber 2.1, the' latter serving as a bearing in'which eccentric 20 revolves. One 'reason/for providing"A -an .internal thread 28" rather than separategrooves is' the.

simplicity of manufacturing, another important object is toobtain a: helicaldepression in the Arubber act: as a bearing on eccentric .is greatly increasedif: .1I

4. ing separation of the outer covering portion from the core due to inertia forces during operation of the pump, I provide a plurality of evenly spaced ings together or to provide'mechanicalineans for anchoring the outer covering to the core so that the impeller is capable of operating under higher pressures even if the adhesive bond between covering'and core is imperfect or if there is no such bond at all. After the covering is molded to the tinues for sometime before the pump is used.

This-shrinkage serves to produce a considerablek tension in the covering and in the tendons extending through holes 39, so that the covering adheres tightly to the core. Another: function .of holes 39 to permit a limitedflowofcovering material from the insideV portion of impeller 2|. :to theoutside toV prevent excessive-pressure on fthe bearing surfacein case.' of. material swelling.. While rubber or synthetic rubberimay be considered.incompressible, they .nevertheless may be subject to swelling when in contactwith certain substances.. of which'. the pumping mediummaybe one. vNear the ends ofI the bore. in impeller 2| excessive pressure may be y'relieved through the layer of covering 'materialienL the lateral faces of the impeller. Accordinglvithe radial holes 39 particularly serve to:relieve"ex cessive. pressure in the central portion of f't'hel. impeller.- A certain flow of material is alsorevquired on the outside surface of impeller 2| whose outer periphery contacts the internalisurfaceof housing I0. Due to the yieldabilityfof the material a better seal .between impeller-LandV housing is obtained as theviinpellervdiameter plusfthe stroke may be,` actually .larger thanthe diameter of the internal bore .of housing"||l..i In consequence, flow of material near the. pointof contact takes placezin'a peripheral direction,`whch is the reason formaking grooves 28K-or ridges 28 `in core 25 parallel. While it islwellrknown that an impeller ofrubber-like resilient material -hasseveraladvantagesl which.;perinitlle`ssaccuracyY in the componentzparts, and also A'allow the .passage of-certain solidsiny the.-l pumping .medium without damageto the pump',I wish to -point outparticularly that'with thelproperf meltallic core as described the characteristicsf' the impeller can be greatlypirnproved topermit greater speeds and .higher fworking v pressures. Also, I have found that by letting the synthetic Y 20'- rather than metallic core. 26Y .the .lifefof such 'bearing ,Of importance, ridges.` 29 extend I circumferential'ly of core 26 only for a short distance and limit the yieldability of molded covering?! only Within the port..openings. In 'this manner-a tight :liquid'seal is maintained .while v'the impeller 1s on upper dead center. which is 'af vpa'rticularly from solids entrained -with fthei .liq1iid'; 'being pumped. The sides-of the impellers arefchaintiered. @relieved asauofrigure 1, .to eliminate :the side lfrictionat, the inner; portlon.'s, iof the impellers and to provide passages through which pumpingyuid may pSsNfromslots 25 tothe .bearings for lubrication. The flow'ofuld occurs A,bgg-virtue. of; .they pumping .action i which.; takes Place in' Slots f'f.' causing. a surge bac-kammen between the slots through chamfers 40 and between the bearing surfaces of the impellers and eccentrics 20.

During pump operation the impellers gyrate in the pumping compartment to carry the liquid which ows to the pump via nipple 31 from intake to discharge, whereon it is forced outwardly through nipple 38. While the angularity of impeller slot 25 with respect to divider plate 30 is continuously changing, the resulting interference is effectively absorbed in displacement of the covering 21 without adverse effect on the sliding liquid seal therebetween.

It will be understood that various changes may be made in details of the construction and operation of the pump of my invention as compared with the above description of a preferred embodiment thereof, which are within the scope of the sub-joined claims.

While the preferred embodiment shows a pump having a pair of impellers to provide a balanced action, it is apparent that any other number of impellers or a single impeller could be used. Also, it should be understood that the term rubber or synthetic rubber is here intended to denote any resiliently deformable synthetic or rubberlike material.

I claim:

1. A cylindrical impeller for a pump as described comprising a hollow cylindrical metallic core having radial holes, spiral threads in the inner periphery of said core, spaced circumferential peripheral grooves in the outer surface of said core and having their axis on the axis of the core, and a covering of rubberlike material surrounding said core on the inside, on the sides. and on the outer surface, said rubberlike material extending through said radial holes to anchor the outer portion of said covering to the inner portion of said covering, the grip of said covering around said core being substanmuy intrested Que i0 shrinkage 0f seid rubberlike material after the molding process, said inner portion of said covering providing a bearing for a revolving driving member of said pump, said radial holes having their outer ends terminating in the bottoms of the circumferentialy peripheral grooves.

2. A cylindrical impeller for a pump as described comprising a hollow cylindrical metallic core having a plurality of radial holes, a plurality of circumferential grooves in the outer periphery of the core, a spiral continuous groove in the inner periphery of the core, a covering of rubberlike material under tension tightly surrounding said core on the inside, on the sides, and on the outside, said rubberized material entirely lling all of said grooves, and tendons of said rubberlike material under tension extending through said radial holes to tie the inner and outer portions of said covering together, the tension of said rubberlike material being produced by shrinkage after the molding process. 3. The construction as claimed in claim 2, the sides of said impeller having relieved portions to reduce friction and to aid lubrication.

WALTER EICKELE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES 

